1. Field of the Invention
The present invention relates to an image processing method and apparatus, in which image data obtained by photoelectrically reading an image on a film, in which a region not including a pre-exposure region having a predetermined image exposed in advance is used for photographing, is subjected to predetermined image processing, thereby forming output image data.
2. Description of the Related Art
Usually, photographic films are placed on the market in an unexposed state. However, for example, in recreational facilities such as an exhibition site and an amusement park, there is a case in which films with images such as a copy for advertisements relating to an exhibition, a character, and a mascot being in advance exposed thereon (pre-exposure images) may be sold. Particularly, in many cases, films with pre-exposure images being recorded thereon are sold as a so-called lens-fitted film package (LF).
In the lens-fitted film package (LF) with pre-exposure images being recorded thereon, a mask is in advance applied to a pre-exposure image portion and the pre-exposure image portion is not exposed during photographing. As a result, a film image with a practically photographed image and a pre-exposure image being combined can be obtained.
The film including a pre-exposure image as described above is processed in the same way as in an ordinary film.
On the other hand, there has been known in recent years a technology in which frame images recorded on a photographic film are photoelectrically read by a reading sensor such as a CCD, image processing such as enlargement/reduction or various corrections is performed for digital image data obtained by the reading, and based on the digital image data for which the image processing has been performed, images are formed on a recording material by modulated laser light.
In the technology in which frame images are read by a reading sensor such as a CCD in a digital manner, in order to realize accurate image reading, a frame image is preliminary read (so-called pre-scan), reading conditions corresponding to density of the frame image, and the like (for example, an amount of light irradiated on the frame image, charge accumulation time in a CCD, and the like) are determined, and the frame image is read again based on the determined reading conditions (so-called fine scan).
In an image photographed using a lens-fitted film package (LF), distortion occurs in a marginal image or an amount of light in a marginal image decreases, due to aberration or distortion of a lens. In this case, an amount of light in a marginal image in which a subject such as a wall other than a main subject is located is smaller than that at the center of the image in which a main subject is located at a high probability. As a result, in a finished print, a wall portion becomes dark and four corners are shaded.
In order to solve the above-described problem, distortion correction is performed, or correction in which an amount of light decreased in a marginal image is calculated from a histogram of a photographed image, or the like and is further added for each pixel or to an entire image is performed (ambient light quantity correction). Both of these corrections are each referred to as lens correction.
By performing these corrections, distortion in the marginal image is improved and the marginal image becomes bright. Accordingly, a proper image can be obtained.
The above-described distortion correction and ambient light quantity correction are both effective for an image practically photographed via a lens, but are not required for a pre-exposure image having an image recorded in advance. That is, when the distortion correction and the ambient light quantity correction are performed for a pre-exposure image exposed in a most suitable state, negative distortion occurs or an excess amount of light is applied in an image for which the corrections are performed.
In view of the above-described facts, it is an object of the present invention to provide an image processing method and apparatus, which allows most suitable image correction (particularly, distortion correction and ambient light quantity correction) for a film on which a pre-exposure images are recorded in advance.
In accordance with a first aspect of the present invention, there is provided an image processing apparatus comprising: image reading means for reading an image recorded on a film, the image including a pre-exposure region on which a predetermined image is in advance exposed, and a photographing region for photographing; image separating means which separates image data of the image read by the image reading means into pre-exposure image data for the pre-exposure region and photographed image data for the photographing region; correcting means which calculates image processing parameters and effects image correction for at least one of the pre-exposure image data and the photographed image data; and image synthesizing means which combines the pre-exposure image data and the photographed image data, at least one of which is corrected by the correcting means.
According to the first aspect of the present invention, the pre-exposure image (data) and the photographed image (data) are in advance separated from each other by the image separating means. The correcting means sets image processing parameters of at least one of the separated images independently and performs image corrections (for example, lens correction, color correction, and density correction). As a result, corrections suitable for at least one of the images are made. That is, the pre-exposure image is generally recorded optimally in a normal state. On the other hand, in the photographed image, a recording state, such as underexposure, normal exposure, overexposure, and super overexposure varies depending on a photographing state. Accordingly, it becomes necessary that the pre-exposure image and the photographed image be separately subjected to image corrections.
The pre-exposure image and the photographed image, at least one of which is subjected to image corrections, are recombined by the image synthesizing means to form one frame image on the film.
In accordance with a second aspect of the present invention, in the first aspect of the present invention, the correcting means corrects the photographed image data based on image processing parameters calculated based on only the photographed image data, and the correcting means further corrects the pre-exposure image data based on image processing parameters previously set based on the film.
According to the second aspect of the present invention, the pre-exposure image is, as described above, exposed optimally in a normal state. Further, since the pre-exposure image is not an image photographed through a lens, image processing parameters can be set in advance.
Accordingly, by calculating only image processing parameters of the photographed image from the photographed image, the image processing speed can be improved.
In accordance with a third aspect of the present invention, there is provided an image processing apparatus comprising: image reading means for reading an image recorded on a film, the image including a pre-exposure region on which a predetermined image is in advance exposed, and a photographing region for photographing; storage means for storing pre-exposure image data for the pre-exposure region, and pre-exposure image processing parameters including at least one of positional information of the pre-exposure image data and printing information of the pre-exposure image data; image separating means which separates image data of the image read by the image reading means into the pre-exposure image data and photographed image data for the photographing region; correcting means which calculates image processing parameters of the photographed image data and effects image correction for the photographed image data; image data reading means for reading the pre-exposure image data from the storage means; and image synthesizing means which combines the pre-exposure image data read by the image data reading means and the photographed image data corrected by the correcting means.
According to the third aspect of the present invention, since the pre-exposure image is in advance recorded on the film, pre-exposure image data and image processing parameters for the pre-exposure image, including the position of the pre-exposure image on the film and printing information, can be recognized. For this reason, the pre-exposure image data, the positional information, and the printing information (at least one of them) are stored in the storage means.
On the other hand, the photographed image is subjected to various image corrections by the correcting means, so as to form proper image. Subsequently, in the image data reading means, the pre-exposure image data stored in the storage means is read, and the photographed image data and the pre-exposure image data are combined by the image composite means. At this time, the positional information of the pre-exposure image data is also read at the same time, and therefore, the pre-exposure image and the photographed image are properly combined with each other.
In the foregoing, correction for the pre-exposure image is omitted. The reason why is that, assuming that the pre-exposure image is generally recorded in a proper printed state, corrections are not required for the pre-exposure image. However, the present invention is not limited to the same. Depending on a photographing state of the photographed image (for example, in a case in which the photographed image is in a super overexposure state, even if the correction is made for the photographed image, a rather bright image is obtained by the correction), the pre-exposure image may be corrected so that a composite image of the photographed image and the pre-exposure image is obtained with no sense of unnaturalness being visually produced (namely, a slightly bright pre-exposure image is suitable for a slightly bright photographed image).
In accordance with a fourth aspect of the present invention, in the image processing apparatus relating to the third aspect, the storage means stores a plurality of pre-exposure image data based on identification means for identifying the pre-exposure image data, and the identification means corresponding to a pre-exposure image recorded in advance on the film is provided for at least one of the film and a cartridge in which the film is accommodated.
The read pre-exposure image may be stored in the storage means, and in most cases, the pre-exposure image is generally provided as a template. Accordingly, in the fourth aspect of the present invention, a plurality of kinds of pre-exposure images may be stored, as templates, in storage means. In this case, an identification code is given to each of pre-exposure images and the identification code is recorded on a film or a cartridge in which the film is accommodated. As a result, by reading the identification code from the film or the cartridge during image reading, the pre-exposure image can be specified, and pre-exposure image data corresponding to a pre-exposure image previously recorded on the film can be read from the storage means.
In accordance with a fifth aspect of the present invention, there is provided an image processing method comprising: an image reading step for reading an image recorded on a film, the image including a pre-exposure region on which a predetermined image is in advance exposed, and a photographing region for photographing; an image separating step which separates image data of the image read in the image reading step into pre-exposure image data for the pre-exposure region and photographed image data for the photographing region; a correcting step which calculates image processing parameters and effects image correction for at least one of the pre-exposure image data and the photographed image data; and an image synthesizing step which combines the pre-exposure image data and the photographed image data, at least one of which is corrected in the correcting step.